DESCRIPTION The objectives of this research proposal are to develop and utilize catalytic asymmetric processes in the total synthesis of novel marine natural products. In particular, the development of the catalytic asymmetric inverse electron demand Diels-Alder reaction for the enantiospecific synthesis of cis-2,4-disubstituted tetrahydropyrans. This methodology will be utilized to assemble key intermediates in a concise synthesis for the novel marine natural product, azaspiracid (1). The E and I ranges of azaspiracid are particularly well suited for synthesis using of this methodology. Azaspiracid is important target since it is not readily available from natural sources and there has not been material available for biological testing (vide infra).